There are a lot of websites out there with kids science projects -- you just have to add the theology.
ZOOM (PBS TV show) -- https://www.pbslearningmedia.org/collection/zoom/
Kid Science
Science Made Simple
Santa Barbara Science Center
Museum of Science
You can also find other sites by typing "science kids projects" into your internet search engine.
I like to browse stuff like this and think of how different projects might fit with lessons in the scope and sequence.
Lisa
Rotation.org's Sunday School Lesson & Resource Forums

We are an online community of Sunday School teachers, Christian educators, and pastors creating, collecting, and sharing free and premium Sunday School lesson plans, creative ideas, and discussion. We are also the official website of the Workshop Rotation Model (The "WoRM"), a creative way to organize and teach Sunday School. Visit our Bible story lesson forums. View our creative Writing Team Lesson Sets. Explore our 24 downloadable Bible story software programs. Get a free Registered Membership or become a Supporting Member for full access to all site resources. Learn more about our volunteer-led, ecumenical, non-profit, ad-free resource ministry!